At present box joints are cut on a fixed table saw, or the like by passing the material to be cut, on edge, over a dado cutter or a wobbler saw blade. The precision of the resulting cuts then depends not only on the accuracy of any gauge used, but also on the ability of the operator to hold the material to be cut on edge precisely perpendicular to the cutter. With large pieces of material, it is awkward to position the material, and hold it in place while traversing the cutting tool.
Known types of gauge for such prior art box joints cutters are shown for example in U.S. Pat. Nos. 2,777,485 granted to B. J. Farrow on Jan. 15, 1957, and 2,972,366 granted to A. Caruso on Feb. 21, 1961. In both of these prior patents, gauges are shown for attachment to fixed or bench type saws, to control the spacing of successive cuts. The material to be cut is moved past a fixed cutter. Canadian Pat. No. 641,661 granted to the Porter-Cable Machine Company on May 22, 1962, discloses a router guide mounted from the upper surface of a baseplate and intended to engage an edge of a work piece to guide the router. This structure is complex involving rods slideably mounted and secured in boxes by screws. A guide plate with a depending flange is fixed to the rods by a support plate. Various other parts are also required to complete the structure.
Box joints at one time used to be cut by hand. This was both time-consuming and subject to mistakes of marking and/or imprecise cutting. Machines were later invented with multiple cutting blades into which the material was fed --those machines are complex and correspondingly expensive. Other means have also been devised for cutting box joints. These included a mobile apparatus sliding on top of table saws, or table-mounted routers, as disclosed in the aforesaid U.S. Patents. However, they were limited by the maneuverability and the wieght of the material being processed.